Improvement in electrical photometer-balances



w. w G00 0 w N Elec tri cal Pho tometer Balances. N0.158,6\36.

Pate nted Jan. 12, 1875.

ml'nesses;

UNITED STATES PATENT OFFICE.

WILLIAM W. eoonwin, or oAMnEn,-nEw. JERSEY.

' lMPROVEMENTlN ELECTRICAL PHOTOMETER-BALANCES.

- Specification forming part of Letters Patent No. 158,636, dated Jaruarv 12,1875; application then August 21, 1874'.

To all whom it may concern: r

Be it. known that I, WILLIAM W. Goon- WIN, of Camden, in the county ofCamden and State of New Jersey, have invented an Improved Balance, ofwhich the following is a specification:

Theobject of my invention is to produce a more readily adjustable andaccurate balance for determining the number of grains. of the sperm of acandle consumed in a given time,

' in testing the quality of anyilluminatinggas by a photometer, andespecially when the said photometer is iii-connection with an electricbattery.

The peculiarities of my invention will be readily understood by thefollowing description, with reference to the accompanying drawings, inwhich- Figure l is a perspective view of the balance in equipoise,supporting a test-candle,

on its fulcruros and hearings in the usual manner, supported on. thepostB, while its weight-points support the candle and its pendulous socketl). The said socket is provided with an adjustable ring, at", with thebearings for the weightpoints attached, and has also a slot, an innerslide, and a bindingscrew, d, whereby the height of the candle O can bereadily adjusted to correspond with the height oi the usual gasburn'erof a photometer. The rimmed or Banged disk d, which is fixed by a stemto the lower end of the socket l), is intended to serve the doublepurpose of keeping said socket plumb, and at the same time aii'ording asuitable receptacle for shot or other weights, if at any time the le verA, with "its attachments, should be too heavy to allow the lever to bebrought into equipoise. The said powerarm of the lever -1 made aboutthree times the-length oi the w ei ght-arrmand its extreme endpassesthrough a roomy slot, 6, in an upright, c. which is fixed post B being.fixed to rest upon the opposite end of said base-plate, which latter isinsulated and fixed in a horizontal position upon any suitable part ofthe photometer to which grain. Above the straight upper edge of thelonger arm of said lever, and parallel thereto, is a stiii' rod, a.Supported rigidly by and in posts 4. 4 at about half an inch. abovethestraight upper edge of A, and so as to slide freely though accuratelyon said bar 01/, there is secured a small weight, 5, having a thin bladeprojecting downward therefrom on each side of the lever A, so as tocorrespond with the grain division marl: thereon beneath said weight 5at whatever position, the said weight may be between 0 and 50,inclusive.

About an inch below the longer arm of A, and parallel with the upperstraight edge of the same, there is fixed another. rigid bar, 6,'

by meansof two posts, Y and 8. On this bar 6 a microinetrical adjustingdevice, F, is placed, consisting of a sleeve, f, which has finescrewthreads out around on its outer surface, and a traversing; weight,f applied thereon. One end of the sleeve has a head, f which is tittedwith a small binding-screw, 9, so that the whole device F can he slidalong in either direction upon the bar 6, and by means of said screw 9fixed at any point on the bar between the posts 7 and 8, for thepurposeof bringing the lever and its attachments into equipoise.

Directly below the post 8 there is fixed upon the base E a pair ofelectromagnet s, Gr,

one end of the coil-wire being connected to said base E by thebinding-screw g, while the other end of said coil-wire is intended toserve as the returnwire to a battery, (not shown,) while the armatureg"of the coil-cylinders is upon the base-'plate E of the balance-Abe fixedto a projection of the post 8, so as to be at a short distance from thetop of the electro-magncts Gr when the lever A is horizontal,substantially as shown in Fig. 1.

Projecting downward from the under side of the extreme end of the longerarm of le ver A, there is fixed a platinum stem, 10, and adjustablysecured directly below said stem 10 is a glass mercury-cup, H, having aplatinum wire extending down from the inner side of the same, throughits bottom, into contact with adjustable supports, and thence into eonnection with a wire coming from a battery, (not shown;) and this cup Hbeing nearly filled with mercury, a complete electric circuit will beformed between the balance and the battery whenever the platinum stem 10comes down into contact with the mercury in the cup, the lever A, postB, and base E forming a part of said circuit.

The adjustable weight K, above the line of the bearing-points of thelever A, is fixed by' the manufacturer at the proper height to bring thecenter of gravity of the lever and its fixed appendages at a point avery little below the center of its motion, to produce delicacy in thevibratory motions of the said lever, as is well known to manufacturersof such apparatus.

The mercury-cup and its supports are insulated, in respect to thebalance, by means of a layer of vulcanite between the same and itssupportingbracket l1; and the whole bal ance is insulated upon itssupport by means of a layer of vulcanite between the latter and the baseE of the balance.

The adjustable support forthe mercury-cup ll consists of a post, I. onthe bracket 11, (with a layer of vulcanite, 12, between,) and a post,1., having astem which enters a socket-hole in the post I, and can beraised, lowered, and turned around, as occasion may require,'andcan'also be fixed at either position by means of a binding-screw, 13.The movable post z" carries the mercury-cup H by means of a bent arm,14, which is attached to said post i by means of a rotarythumb-and-finger stem, 15, which passes horizontally through the saidpost and screws into connection with the arm 14, and is held in anyrequired fixed position by means of a binding-screw, 16. By means ofthis adjustable support the mercury-cup H can be readily raised,lowered, or swung around, as occasion may require.

The wire comin gfrom the battery (not shown) enters a hole in the lowerpart of post I, and is secured therein in the usual manner by a binding-screw, 17, and the posts, arm, and platinum wire through the bottom ofthe cup, all being mad-e of conducting metal, will form, with themercury, part of the electric circuit which is to pass from thebattery-to and through the balance, as will be explained.

In the upper end of the post 0" there is a sliding stem, 18, the lowerend of which is fixed to a cross-bar, 19, which also slides in theopening 6 above the arm of the lever,

hold the sliding stem 18 down upon the arm of the lever.

The whole balance, includ ng its base E and its connections, except themercury-cup and the insulating vulcanite layers, is made of conductingmetal, so that when the platinum stem 10 comes into contact with themercury in the cup H an electric current will pass from a batterythrough the mercury, balance,

and the electro-magnet Gr, back again to said battery. I

In testing as to thenumber of grains of the sperm of a candle that willbe consumed in, say, ten minutes time after the candle has been ignited.the operator places the-indicat ing-weight 5 at 0, moves the,mercury-cup aside, ignites the candle, and then slides the adjustingdevice F along on the bar 6 until the lever A of the balance comes tonearly a horizontalposition, and fixes the said device F by means of thebinding-screw 9. He now rotates the micrometrical weight f'on thescrew-cut sleeve f, until the index-pointer a nearly coincides with themiddle mark on the scale a, and'thus indicates that the lever A is innearly a horizontal position; then brings the mercury-cup H directlyunderthe platinum stem 10, and adjusts its height so that the surface ofthe mercury therein will' he, say, the twentieth of an inch below thepoint of stem 10. The candle havingassumed its nor-- mal burningcondition when the index-pointer a coincides with the middle markofscale a,

he slides the weight 5 to 20', starts the clock of the photometer, andthe test proceeds to theend of the ten minutes test.

The wires leading from and to the. battery through :t-he balance, itwill readily'be seen that, at the instant twenty grains of the sperm ofthe candle C have been consumed, the point of the platinum stem 10 willcome into contact with the mercury in the cup H, and an electric currentbe produced through the balance, and that the said contact will besteadily maintained by the armature g, which has at the same time beenbrought into contact with the electromagnetic coil-cylinders G.

It will readily be seen that, if the circuitwire returning from thebalance be put in connection with a valve which will be opened thereby,so as to cause a puff of air to blow out the candle at the instant theplatinum stem touches the mercury in the cup H, the exact amount of thesperm of the candle consumed in the ten minutes specified will beaccurately known.

The said connection and air-valve arrangement is shown and described ina separate specification and drawings, and w l be under stood by areference thereto.

I claim as m y invention-- 1. The combination, in a balance forhotometeis, substantially as described, of the platinum stem 10 ineenteet with the mercury mierometiical adjustingaveight F and the bar inthe cup H, as set forth.

6 with the power-arm 0f the lever A. v i T 7 2. The eleetro-magnet G andthe armature- ILLIAM GOOD bar g", 1-21 combination with thepewer-arm 0fWitnesses: the lever A, arranged as described, fer the I BENJ. MORISON,purpose of holding down the lever A, with its WM. 11. MORISON.

